Since the advent of the ducted fan gas turbine engine for the powering of aircraft, the ratio of the thrust produced by the fan relative to that produced by the associated core gas generator, has increased several fold. In order to achieve this the fan dimensions have increased, with a consequent increase in the dimensions of its associated cowling which provides the ducting therefor.
The increase in the dimensional proportions of the fan cowl has resulted in an increase in the aerodynamic loads experienced thereby during operation on an associated aircraft. This is especially the case during take off of the associated aircraft when the plane of the cowl air inlet is at an angle to the direction of movement of the aircraft which results in the ambient air flowing into the intake in asymmetric manner.
The asymmetrical aerodynamic load applied to the fan cowl is transferred via the fan outlet guide vanes to the core gas generator which in prior art arrangements is rigidly connected to the inner ends thereof. Severe bending of the core gas generator results, which in turn causes, inter alia, compressor blade tip rub on the inner walls of the compressor casing which forms a part of the core gas generator. The operational efficiency of the engine is thus impaired.